pne 516 Pre-Schooner 2

8/7/2019 pne 516 Pre-Schooner 2

1/69

e . s : D \PNE-516FINAL REPORTI ), 'J l.' t

( .' c~-\ :','7'/Jv

UNITED STATES ARMY CORPS Of ENGINEERS

BRUNEAU PLATEAU, IDAHO30 September 1965

PRO J E C Tr B E - s c n O O N E R D

POSTSHOT GEOLOGIC AND ENGINEERINGPROPERTIES INVESTIGATIONSl~TR'BUTION ST~TEMENT A ALTON D. FRANDSENApproved for Pubh? ~elea~ S. Army Engineer Nuclear CraterinJQ...\.~ro, D' tr'bution Unlimited . . . ~.IS I Llver.1 orq~a'l" ,.- ~

(~- > 'rr' f'n11 \-~,t 'r S - .; '. ~ :. '. ,,j!) , "

U, S, Army Engineer N'~clearGrClt:fTng'G'~ouplivermore, Cal ifornia ISSUED: NOVEMBER 1967d - C J f c : > 0 ?


2/69

Printed in USA. Available from the Clearinghouse for FederalScientific and Technical Information, National Bureau of Standards,U.S. Department of Commerce, Springfield, Virginia 22151Price: Printed Copy $3.00; Microfiche $0.65.


3/69

PROJECT PRE-SCHOONER IIPOSTSHOT GEOLOGIC AND ENGINEERINGPROPERTIES INVESTIGATIONS

Reproduced FromBest Available Copy

PNE-516

Alton D. FrandsenU. S. Army EngineerNuclear Crate ring GroupLivermore, CaliforniaSeptember 1967

2 0 0 1 1 1 0 5 1 0 11


4/69

2

HH


5/69

ABSTRACT

The Pre-Schooner II Event was a chemical explosive single-charge crateringexperiment in hard, dry rock. The detonation was centered 71 feet below the groundsurface and consisted of approximately 85.5 tons of nitromethane. The explosion pro-duced a crater with an apparent radius of 95.2 feet and an apparent crater depth of60.7 feet.

Postshot explorations of the crater consisted of excavating three radial trenchesthrough the lip material and then extending two of the trenches into the fallback withinthe crater. Both bulk densities and block-size distribution of the ejecta and fallbackwere obtained. Bulk densities averaged 103.8 pcf except for an anomolous value of93.1 pcf in one trench. Block sizes varied from fines of clay size to blocks greaterthan 6 feet in diameter.

The true crater radius and the lip upthrust were measured at the three trenchesand averaged 100 feet and 11 feet, respectively.

The crater slope angles measured before, during, and after completion of thefallback excavation averaged 37, 42, and 38 degrees, respectively.

3


6/69

Project Pre-Schooner II was a chemical explosive cratering experiment conductedby the U. S. Army Engineer Nuclear Cratering Group as a part of the joint AtomicEnergy Commission-Corps of Engineers nuclear excavation research program. Thisreport summarizes the preshot geologic conditions at the site and presents the resultsof the postshot investigations. Preshot field investigations were conducted during thespring of 1965. Postshot investigations were accomplished in the spring of 1966.

Postshot investigations were performed under the supervision of A. D. Frandsen,NCG. Directors of NCG during conduct of the study and preparation of this report wereLieutenant Colonel W. J. Slazak and Lieutenant Colonel M. K. Kurtz, Jr.

PREFACE

4


7/69

CONTENTS

ABSTRACTPREFACECHAPTER 1 - INTRODUC TION1.1 Description of Project1.2 Purpose and Scope of Postshot Investigations

1.3 Scope of Report1.4 Background1. 5 Project Location and Accessibility

CHAPTER 2 - PRESHOT SITE CONDITIONS.2.1 Geology and Physiography2.1.1 Vitrophyre2.1.2 Vitrophyre Breccia2.1.3 Felsite2.1. 4 Overburden

2.2 Physical Test Data2.3 Field Data2.3.1 Geophysical Test Results

2.3.2 Borehole Logs2.3.3 Borehole Photography2.3.4 Examination of Emplacement Hole and ExplosiveCavity

CHAPTER 3 - POSTSHOT INVESTIGATIONS3.1 Scope of Investigations3.2 Sequence of Execution3.3 Excavation Procedures3.4 Bulk Densities3.4.1 Weighing Procedures3.4.2 Volume Determinations

3.5 Grain Size Distribution3.6 Trench Mapping

CHAPTER 4 - POSTSHOT RESULTS AND DISCUSSIONS4.1 Bulk Density4.2 Grain Size Distribution4.3 Trench Mapping4.4 General Observations4.4.1 Slope Adjustments Prior to Postshot Excavations4.4.2 Slope Adjustments During Postshot Excavations

4.4.3 Slope AnglesCHAPTER 5 - CONCLUSIONSREFERENCESAPPENDIX A - RESULTS OF PRESHOT UPHOLE SEISMIC SURVEYAPPENDIX B - PRESHOT BORING LOGS OF PRE-SCHOONER IISITE AREA

APPENDIX C - LIST OF PRE-SCHOONER II REPORTS

3477799101111121212121314141414142121212230303031313232323742424343474951

5763

5


8/69

FIGURES

TABLES1.1

CONTENTS (Continued)

Frontispiece Pre-Schooner II crater 281516172223242526

27283133343435

36383940414343444546535455

9111315293337374252

1.12.12.22.33.13.2

Location and access mapLocation of geophysical surveys and boreholesAverage physical properties of media at Pre -Schooner II SiteLog of emplacement holeLocation of trenchesPostshot aerial photo prior to commencing excavations(photos grouped for stereoscopic viewing)Postshot topographic map prior to commencing excavationsAerial photo prior to excavation of fallback (photos pairedfor stereoscopic viewing)

Topographic map prior to excavation of fallbackAerial photo after completion of all excavations (photosgrouped for stereoscopic viewing)Topographic map after completion of all excavationTypical cross sections for various stages of trenchexcavationGrain size distribution curve for Trench No. 1Grain size distribution curve for Trench No.2Grain size distribution curve for Trench No.3Grain size distribution curve for crater fallbackComparison of predicted block size for two majormaterials, and postshot fallback and ejecta mechanicalanalysesGround profiles from Trench No.1Ground profiles from Trench No.2, west wall

Ground profiles from Trench No.2, east wallGround profiles from Trench No.3Diagramatic segregation of block sizes in craterDiagramatic illustration of mode of failure during fallbackexcavationProfiles bearing S40W of apparent crater illustratingslope adjustment stagesAerial photo 14 months after completion of all excavationTopographic map 14 months after completion of excavationAverage velocities (slant-distance corrected)Internal velocitiesAverage velocities from shot to surface (slant-distancecorrected)

3.33.43.53.63.73.84.14.24.34.44.5

4.64.74.84.94.104.114.124.134.14A1A2A3

2.12.22.33.14.14.24.3

Data on Craters for Which Engineering Properties InvestigationsHave Been PerformedStratigraphic SequenceSummary of Preshot Physical Test DataTabulation of Preshot Boring Coordinates and DepthsPostshot InvestigationsSummary of Bulk DensitiesDistribution of Rock Type in Lip Ejecta with Respect to SizePreshot Percentage Distribution of Rock Types Within CraterAreaUplift and True Crater RadiusSeismic Uphole Survey

4.4Al

6


9/69

CHAPTER 1INTRODUCTION

1.1 DESCRIPTION OF PROJECTProject Pre-Schooner II was a chemical explosive, single-charge cratering

experiment in hard, dry, rhyolite rock executed by the U. S. Army Engineer NuclearCratering Group (NCG) as a part of the joint Atomic Energy Commission-Corps ofEngineers nuclear excavation research program. Pre -Schooner II was detonated on30 September 1965 at 1709:59.2 Mountain Standard Time on Bruneau Plateau, approxi-mately 40 miles southwest of Bruneau, Idaho (Figure 1.1). The emplacement hole wasat the following coordinates: Longitude W 115034' 25.203"; Latitude N42 24' 02.943"(Modified Idaho State Coordinate System -N 267,639.53; E 547,783.11). The cavity,centered at a depth of 71 feet below ground surface, contained approximately 85.5 tonsof nitromethane (CH3N02) at zero time. The detonation resulted in a crater with anapparent crater radius of 95.2 feet, an apparent crater depth of 60.7 feet, and anapparent crater volume of 24,780 yd3

1.2 PURPOSE AND SCOPE OF POSTSHOT INVESTIGATIONSWhen an excavation is produced by explosive methods, the physical properties of

the surrounding media are appreciably altered. The extent and nature of these changesare of prime importance in evaluating the usefulness of the excavation for engineeringpurposes. The objective of the Pre -Schooner II postshot investigations was to examinethe engineering properties of the crater produced by the detonation. Data developedfrom these investigations will be used in the continuing program to develop methodsfor predicting the shape and character of the disturbed zones surrounding a crater basedon the results of preshot explorations.

In order to accomplish this objective, the program was designed to obtain infor -mati on concerning the geometry of the crater and the characteristics of the zones ofdisturbance. These zones of disturbance include fallback, ejecta, and the rupturedzone beyond the true crater boundary.

The scope of the Pre -Schooner II postshot investigations included:1. Determination of true crater dimensions by trenching through the ejecta and

fallback material into the rupture zone2. Determination of the bulk density of the ejecta by measuring the volume of,

and weighing, the material excavated during trenching

7


10/69

/' O.. ~h I~RUNEAU

\\~ HOT SPR INGS- ,\'''~'-I~ \~ \,

\,,,,\,,\,,,,,,r n " " " : ! l S ~ g ; s ~ \ : " ,

GOODING

1II~if~ 00'0

~I~.. . ,.-01

"E 0_ 0We!!i

:...=!!!!::"",,~===::l,,!!!!!!!!!!!!!!!!!!!!!!!!..i::===:::!l""!!!!!!!!!!!!!!!!~IO unliT! MILli

LEGEN D '

-----,@FEDERALHIGHWAY

- - - -@-- - - PAVED ROAD I UQHT DUTY----------------- IMPROVED DIRT ROAD

UNIMPROVED 01 RT ROAD

_---_-_.--- COUNTY LINE

" TOWN OR RURAL COMMUNITY

I),IIII,,\\

" \ IL_ - - - - - - _\.!!!':!o!!_C~n_tL_ - - -1 '\ ...O wyhee County "" ./

. . . . . . " 1 , , - , ;" ..~", ,------' I" , . . . . . .r: I

..,-"'- I; I/< ~f) - . . . . . . . . ? _ 1 8.;," ---- ........... __ .. 1, :r~ ---

.... ~'a/ ~~..' ot:~...> / !~F'fl'_( IiiIIIIi

Figure 1.1 Location and access map.8


11/69

3. Determination of the size distribution of the ejecta and fallback rockfragments by sieving

4. Definition of the displaced ground surface (lip upthrust) and true cratershape1.3 SCOPE OF REPORT

This report presents a detailed explanation of exploratory techniques and resultsof the postshot engineering properties investigations. Preshot geologic conditions andphysical properties of the media are summarized in Chapter 2. A comprehensivecoverage of Pre-Schooner II preshot geology is contained in the preshot investigationsreport (Reference 1) of the U. S. Army Engineer Waterways Experiment Station (WES).

The major portion of the field work covered by this report was accomplishedduring the period 17 February to 6 May 1966.1.4 BACKGROUND

A number of nuclear and chemical explosive single-charge cratering experimentsand one chemical explosive multiple-charge experiment have been conducted at theNevada Test Site (NTS) to determine cratering characteristics in alluvium and hard,noncarbonate rock. Postshot explorations similar to those undertaken at Pre-SchoonerII have been performed at several of these craters (References 1 through 6). Pertinentdata concerning these craters are included in Table 1.1. The Pre-Schooner II cratering

TABLE 1.1 DATA ON CRATERS FOR WHICH ENGINEERING PROPERTIESINVESTIGATIONS HAVE BEEN PERFORMED

Apparent Average AverageScaled Actual Crater Apparent ApparentCraters DOB DOB Del2th Crater Radius LiE Height Yield

tonsPr e-SchoonerDelta 135 42.7 25.6 46.1 7.3 20Pre -SchoonerCharlie 210 66.5 -1.3 none 16.0 20Dugout= 185 59 34 5 129 8 24 5 100Sulky 185 90 -9.2 none 20.9 85 15Danny Boyb 142 llO 64 106 25.5 420Pre-Schooner II 142 71 61 95 17 85.5aRow crater containing five 20-ton chargesbNuclear

event was a single -charge crate ring experiment in a rock medium less competent thanthe basalt of Buckboard Mesa at NTS; therefore, a postshot exploration of the crater wasexpected to provide meaningful data pertaining to the engineering properties of a craterin a different rock medium.

9


12/69

1.5 PROJECT LOCATION AND ACCESSIBILITYThe Pre-Schooner II Event was located in Owyhee County of southwestern Idaho.

The site is roughly 65 road miles south of Mountain Home, Idaho. Figure 1.1 is anindex map showing the site location and access roads.

10


13/69

CHAPTER 2PRESHOT SITE CONDITIONS

Extensive preshot surface and subsurface explorations were made at thePre -Schooner II site. These explorations include surface geologic mapping and accesshole logging (References 7 and 8), subsurface core -hole drilling and refraction seismicsurveying (Reference 1), and uphole seismic surveys (Reference 9). General geologyand physiography of the region are treated in References 10 and 11. The followingparagraphs summarize information contained in the above references.2.1 GEOLOGY AND PHYSIOGRAPHY

The Pre-Schooner II site is located in a region commonly known as the BruneauDesert. Itis an area of gently northward sloping topography with occasional low,rounded hills interrupting the monotonous sage-covered ground surface. Canyons ofthe Bruneau River and its tributary streams flowing through the region are narrow anddeep with precipitous, near vertical walls. In the vicinity of the Pre-Schooner II site,the West Fork of the Bruneau River is approximately 800 feet deep.

Bedrock in this region of southwestern Idaho consists of a variety of clastic andvolcanic rocks ranging in age from Miocene to Recent. Bedrock relationships in thevicinity of the Pre-Schooner II site are shown in Table 2.1.TABLE 2.1 STRATIGRAPHIC SEQUENCEFormation Age Description

Recent Flows Upper Pliocene to Recent Local patches or domes ofbasaltic flowsBasalt and interbedlacustrine depositsAcidic volcanics

Banbury Basalt Middle PlioceneIdavada Volcanics Upper Miocene toLower Pliocene

The immediate Pre-Schooner II area is in the Idavada formation which, ingeneral, consists primarily of interbedded silicic latite flows, glassy rhyolite flows,and lava flows .

At the site, to the depths drilled, bedrock is mineralogically a porphyritic glassyrhyolite which has commonly been subdivided into the following textural variations:vitrophyre, vitrophyre breccia, and felsite. A thin blanket of overburden covers mostof the area.

11


14/69

2.1.1 Vitr0l2.hyre. This rock type typically consists of a finely divided blackground mass containing 10 to 20 percent plagioclase phenocrysts by volume. Theplagioclase is primarily lath-shaped oligoclase ranging in size from less than1/64 to 3/8 inch. Texturally, the vitrophyre ranges from dense to vesicular with localzones which are even highly scoriaceous. Perlitic fracturing throughout the vitrophyremakes it very friable and easily crumbled by light blows with a hammer or rubbing be-tween the fingers. When shattered, it breaks down to fragments as small as coarsesand. Iron stains coating the perlitic fractures often give hand specimens the appear-ance of being red. Infrequent joint faces are generally coated with calcareous materialand clayey alteration products.

Thickness of the vitrophyre, including the vitrophyre breccia, ranges fromo to 45 feet. Average thickness in the area drilled is about 25 feet.

2.1.2 Vit:r:2Qhyre Breccia. Mineralogically, the vitrophyre breccia is essentiallythe same as the vitrophyre. Physically, it is a distinctly different rock type. Coresamples show the breccia to be a conglomeration of black glassy vitrophyre fragmentsranging from sand size to several feet in diameter enclosed in a reddish brown, finelydivided, glassy matrix. Petrographic analysis shows the mineralogical composition ofthe fragments and matrix to be essentially the same. The fragments contain the sametype of feldspar phenocrysts and perlitic cracking as found in the vitrophyre.

Stratigraphically and areally, the breccia is irregular, occurring both above andbelow the vitrophyre at some localities and is totally absent in other places. The lackof breccia, as recorded in some holes, may be due to a lower core recovery percentagein those particular holes.

2.1.3 Felsite. The felsite is typically a hard, dense rock, pinkish gray to light

2.1.4 Overburden. The overburden in the Pre-Schooner II area consists of sandysilt and fragments of the three different rock types. Thickness of the overburden rangesfrom 0 to 10 feet and averages about 6 feet over the area of the crater.

gray. At the Pre-Schooner II site it normally underlies the vitrophyre, or vitrophyrebreccia, where present. Mineralogically, the felsite is classified as a porphyriticrhyolite, as are the vitrophyre and breccia. Itdiffers considerably in physical prop-erties and texture from the other types.

Phenocrysts are usually less numerous in the feIsi te, and perlitic fracturing occursonly in localized pods rather than throughout the rock mass.

Joints occur as irregular, coalescing, and bifurcating curved surfaces, sometimeshealed with calcite and sometimes entirely free of any secondary coating. In mostcases, however, preshot joints were fairly tight as seen in the shot cavity and accesshole.

12


15/69

2.2 PHYSICALTEST DATAThe preshot physical test data are tabulated in Table 2.2 according to the three

major rock types. An examination of the table indicates several trends:1. The specific gravity of the three rock types varies slightly (the vitrophyre

breccia is the lowest and the felsite the highest).2. The bulk density (dry and saturated surface dry) is approximately the same forthe felsite and vitrophyre, excluding the vesicular vitrophyre, and slightly lower for the

vitrophyre breccia.3. Average unconfined compressive strength is lowest for the vitrophyre breccia

and only slightly higher for the vitrophyre, whereas the average strength of the felsiteis conaider-ably higher.

4. The modulus of elasticity increases gradually from the apparently weaker andless dense vitrophyre breccia to the felsite.

TABLE 2.2 SUMMARYOF PRESHOT PHYSICALTEST DATAUnconfined

BoringDepth'" b

Bulk Density Specific Compressive Modulus of Poisson'sNumber Description SSD Dry Gravity Porosity Strength Elasticity Ratio

feet pef pcf percent psi psi X 106Vitrophyre2.1 18.1 Massive Vitrophyre 152 150 2.44 1.6 7,320 3.13 0.182.1 26.6 Lithoidal Vitrophyre 153 149 2.50 4.8 3,820 0.84 c2.1 43.7 Vesicular Vitrophyre 134 130 2.43 14.4 3,090 2.50 0.252.6 19.7 Layered Vitrophyre 150 147 2.49 5.8 6,830 2.47 0.102.8 8.4 Mas si ve Vitrophyre 149 146 2.49 5.9 9,010 5.77 0.24

Average 148 144 2.47 6.5 6,014 2.94 0.19Vitrophyre Breccia2.3 43.7 Vitrophyre Breccia 141 137 2.40 8.4 4,450 2.44 0.242.3 44.2 Vitrophyre Breccia 142 138 2.43 9.1 6,410 2.46 0.16

Average 142 138 2.42 8.7 5,430 2.45 0.20Felsite2.1 86.5 Layered Felsite 150 148 2.54 6.7 19,710 4.94 0.192.1 109.7 Layered Felsite 152 150 2.52 4.8 c c c2.10 26.9 Glassy Felsite 147 141 2.49 9.1 5,970 1.20 0.212.10 31.8 Layered Felsite 152 147 2.52 6.5 7,730 2.29 _c2.10 77.4 Massive Felsite 153 149 2.56 6.6 21,940 4.68 0.202.10 108.8 Massive Felsite 154 150 2.54 5.5 17,050 4.59 0.15

Average 152 147 2.53 6.5 14,480 3.54 0.19

aCenter depth of sample tested.bSample description from Reference 1 shown under major rock types used in this report.cData shown as doubtful in Reference 1, malfunction of test equipment, or unable to run test with avail-able sample.

13


16/69

2.3 FIELD DATAInformation on subsurface conditions at the Pre -Schooner II site was obtained

in the field by geophysical methods, core logging, borehole photography, and exami-nation of the emplacement hole and explosive cavity.

2.3.1 Geophysical Test Results. An uphole seismic survey was run in borehole2.12 (Figure 2.1). Explosive charges of 1-1/2 pounds each were successively detonatedat 10-foot intervals, and the results presented in Appendix A were obtained. Asummary of the seismic velocities obtained from the uphole seismic survey is givenin Figure 2.2 together with the average physical properties of the media as determinedfrom laboratory tests. The summary shows a fairly good correlation.

In addition to the uphole survey, two surface refraction seismic traverses wererun along the lines shown on Figure 2.1. Discussion of these data appears inReference 1.

2.3.2 Borehole Logs. Twelve preshot borings were made at the project site.Locations of the borings are shown in Figure 2.1, and Table 2.3 gives the boringcoordinates and drilled depth. Five of the borings (2.1, 2.7, 2.10, 2.11 and 2.12) werewithin the immediate vicinity of the crater, and the detailed logs of these borings areincluded as Appendix B. Detailed lithologic logs of all borings in the Pre-Schooner IIarea and borings drilled during the site selection phase of the Pre -Gondola II projectare contained in an appendix to the WES preshot report (Reference 1). Examinationof the logs shows very poor core recovery in the upper part of the borings which indicatea rather weak, friable material.

The boring logs in Appendix B show that the felsite generally occurs 20 to 50 feetbelow the surface. However, a rock outcrop some 30 feet to the northwest of SGZ isfelsite, which indicates that the combined thickness of vitrophyre and vitrophyrebreccia is highly variable in the site area. Overburden thicknesses within the sitearea varied from 0 to as much a 10 feet within 100 feet of SGZ.

14

2.3.3 Borehole Photog~. Borehole photographs were made in the borings inthe immediate vicinity of the Pre -Schooner II site. Due to the fact that the holes weremade oversize by rod whip during drilling, no useful data were obtained.

2.3.4 Examination of Emplacement Hole and Explosive Cavity. In addition to thecore logs, the ground zero emplacement hole, a 36-inch diameter calyx boring, andthe shot cavity were visually examined. Results of the access hole and shot cavityinspection are shown in Figure 2.3.


17/69

~0 0 -N-o 0 !LO 0~

r-, 00 V"O+OO. . -eLO LOW W,,":+00 2.2 2+00)'/n0 N268,000

~"2.0 ,~

/ 2.4

seism'ic~ 2.3 0 4+00~ 2.5"'-.-/No. 2~~2.1

/"~ 02.11 02.92.80 ? - - 1 .72.1~q .~. Uphole/8+00 2.10 seismic

10+00


18/69

Bulk dryspecific gravity2.20 2.40

Overburden---?----.--,/ Y itrophyre \and _-""'0 ...I vitrophyre -\, breccia6--0 _-/ \X- - - - - - - t s=~- - - -

-+-. . . . . .1 50 I

P . I..c ~rOslty Ig . 60 Io II70 I1 ~ / -I gravity~ -,, FelsiteI,,,6

o 10 20Porosity - %

Compressivestrength - psi3000 13,000 23,000 0~~~~--~--~--~

Seismic velocityft/sec X 103

5 10 15 20 25

l /-I _. ' f > - ' Yitrophyre1/ - and

~\ vitrophrret\. brecc rop./ \~.JC---------\\.\ Compress ive' : ~ ~ 7\\fIIPIIIII_ J

of ielasticity, _"o 4

Modulus ofelasticity - psi X 106

8

Figure 2.2 Average physical properties of media at Pre-Schooner II site(Reference 12).

16


19/69

.s:. . . .(;Z

.s:. . . .: : : JoVI. . . .!3w

-E(;Zo

De :wZooIUVIIurDe :a . . .w_.oIX~


20/69

-0.( ] ) . . _...4-.2~u ce 04- ._>-~.s: QJOlE_ : c = U4-Eo :J'" Ec-( ]) xE 0mEo . . . . c. . . .._'; '3(]) (])0 - - : :Q_U)x-UJ~

oN coNNN "


21/69

-"Q)::Jc. . . . .c0SW...J0IX> -...JUVlVlWUuLL0o0...J

-(;Z. . . . .~~.s:. . . . .::J0Vl

. . . . .0W.s:. . . . .(; .s:Z o _ ~

Q):)


22/69

- 0ill1 ::>o-0c:0. . . . .(;.s:'"ill. . . . : : :0'" N. . . . .c:. Q . -o. . . . . "0 Q~ . . . . :

19-20Figure 2.3 (Continued)


23/69

CHAPTER 3POSTSHOTINVESTIGATIONS

Postshot investigations consisted of excavation in the ejecta, upthrust, and fall-back in order (1) to determine bulk density and grain size distribution and (2) to examinethe upthrust, fallback, and rupture zone.

In excavating through the lip, every effort was made to avoid picking up any of theoverburden which was part of the original ground. This was fairly easy to do in theouter parts of the trenches because of the marked differences between the ejecta andoverburden. However, in the end of the trenches nearest the crater there was somemixing of overburden with ejecta due to the greater difficulty in locating and followingthe contact.3.1 SCOPE OF INVESTIGATIONS

Three trenches (see Figure 3.1) were excavated through the lip. Bulk densitieswere obtained for the ejecta, and an attempt was made to determine the bulk density ofthe upthrust. Part of the material excavated was used for determination of grain sizedistribution. In addition, the trenches exposed profiles of the upthrust ground surface.Detailed mapping of these profiles was accomplished to assist in determining theengineering properties of the crater lip.

Trenches No.1 and No.3 were extended to the middle of the crater (Figure 3.1)to measure bulk density, and grain size distribution, and to expose the rupture zone-fallback contact.3.2 SEQUENCE OF EXECUTION

The postshot exploratory field work began by obtaining an aerial photograph of thecrater and ground surveys for the three trench areas. The ejecta above the upthrustoriginal ground surface was then excavated from the trenches. Trench areas werethen surveyed again, and the upthrust lip material was removed, bringing the trenchfloors down to several feet below the original ground elevation. The trench areas werethen surveyed for the third time.

After the trenches were completed and final surveys made, a major portion of thelip material between the trenches was moved away from the edge of the apparent crater,and aerial photographs and a topographic map were obtained. Excavation of the fallbackinside the crater was then started. When sufficient material had been excavated for abulk density determination and before excavating into the rupture zone, another set ofaerial photographs and a topographic map were made. Excavation then proceeded intothe rupture zone. Eventually, the original three trenches were deepened as far as

21


24/69

Figure 3.1 Location of trenches.

possible. A final aerial photograph and map were made at the completion of all excava-tion. Photographic stereoscopic pairs of the excavation phases, and correspondingtopographic maps, are shown in Figures 3.2 through 3.7.

Concurrent with the excavation, screening of selected material was carried on todetermine grain size distribution curves. The sequence of operations and the dataobtained from each operation are shown in Table 3.1.3.3 EXCAVATION PROCEDURES

Initial excavation through the crater lip consisted of removing the ejecta fromabove the upthrust ground surface which, in Trench No.1, was marked with a coloredgrout strip laid down prior to the event. During excavation of the ejecta, special carewas taken to stay above the upthrust original ground surface. After the ejecta had beenremoved and the volume determined, the trenches were deepened by excavating the up-thrust ground to depths of several feet below the original ground elevation.

In excavating the trenches, digging proceeded from the outer edge of the lip andprogressed towards SGZ. Excavation was stopped short of the apparent crater, leavinga plug at the end of each trench. This was done in order to avoid pushing any of thetrench material into the crater which would have caused some error in the bulk densitycalculations.

22


25/69

23

.. . . . . .bJ)s : :. . . . .~Q). . . . .>C). . . . .0.oC)C JloQ)HQ)+'C JlHo'+-!"0Q)0.gHbJ)Ulo-0

. g _- -C Jls ::o. . . . .~.>C 1 IC)~Q)bJ)s ::. . . . .C)s ::Q)SSoC)o+'Ho. . . . .H0.o+'o. . s : :0.. . . . .C 1 I. . . . .. . .Q)C 1 I- 0. . s : :C Jl+'Uloo,


26/69

. a . - e , o ',46236

,.240\

O-j c f46288.247

\ L N 267,900.250

0-\\ :: , 46265

'N 267,800

D-7~463C'3

'''1267,600!

N 267,500

C-2-..-,.*'9------_-46330 N 267,400

1 t e s e e .32e ' ; ' 2 1 I I ' " 1335 ...1 1r;'34 I [ ;r . ; , l . ~344 '0\ 0-4'-. ~.. --~~~-- ~!_j~ -Noi' i- I ' t I:E:sHOT G Z. . ~ ~ ELEVAT ION 4629.~. .~ .:' ~ .' .' ~g ~ 8 g osFigure 3.3 Postshot topographic map prior to commencing excavations.

24


27/69


28/69

Figure 3.5 Topographic map prior to excavation of fallback.

26

I


29/69

27

.b ns ::. . . . .~Q). . . . .:>(). s . .oo({JoQ)HQ). . . . ,({JHo'+-I'0Q)0..gHllO{{Job- a. . . . . .


30/69

t.._,s

Figure 3.7 Topographic map after completion of all excavation.

28


31/69

TABLE 3.1 POSTSHOT INVESTIGATIONS

Remove ejectafrom rest ofcrater lip

TopographicMap No.1

Weigh excavatedmaterial


Volume basedon Surveys No.and No.2

Trench profil ing

Topograph icMap No.2


Tapograph icMap No.3

Craterslope anglemeasurements

Volume basedon Surveys No.and No.2

Bulk density


rupture zaneObservation and recordingof engineering properties

of rupture zone

29

Screen 20% ofexcavated material

Screen 10% ofexcavated material


Particle size

Partic le sizedistribution


32/69

The fallback inside the crater was excavated with a dragline from the outer endsof the two trenches (No.1 and No.3). The crater excavation was started with the drag-line crane set back about 10 feet from the apparent crater lip, and digging began aboutmidway down the slope. When the upper part of the slope was removed back to thecrane, the bottom of the crater was dug out as deep as possible, after which the cranewas moved back a little farther and the process repeated. The excavated material wasstockpiled alongside the crane and then for weighing, was loaded into trucks with an endloader.3.4 BULKDENSITIES

The methods of handling the excavated material and making volume determinationsfor use in computing bulk densities were different for the fallback and the ejecta.

3.4.1 Weighing Procedures. In all cases the material excavated was loaded ontodump trucks which were then weighed on portable truck scales. Material from thetrench excavation was loaded directly into the trucks as it was removed. The fallbackmaterial was stockpiled near the crane and then loaded into the trucks with the loader.

30

3.4.2 Volume Determinations. The volume of material removed from the trenchesfor weighing was determined from a ground survey run on a 3-foot-square grid pattern.The grid survey was run before and after excavation of the ejecta. After excavation ofthe upthrust, profiles spaced at 10-foot intervals were run perpendicular to the trenchcenterline. These profiles were used to compute the volume of upthrust materialexcavated.

The initial grid for each trench extended from approximately the lip crest in adirection away from SGZfor some distance, depending on the amount of ejecta. Eachgrid extended 45 feet on either side of the trench centerline. Subsequent grids wereextended only a few stations beyond the limits of disturbance caused by excavation. Thesesubsequent grids were also modified to obtain elevations at major slope breaks which didnot coincide with the preceding profile, such as at the toe of the slope bounding thetrench. Figure 3.8 shows a typical profile for the various stages of trench excavation.

The volume of fallback material excavated from the crater was calculated fromtopographic maps made from aerial photographs. Maps of the crater, both pre- andpost-excavation, were cross-sectioned in an east-west direction at 3-foot intervals.Since the cross sections were taken along the same line in both instances, the differencebetween the two represents the end area from which material was removed. A standardend area computational method was then used to determine the volume.

The topographic maps were drawn from the aerial photographs at a scale of 1 inchequals 20 feet and a contour interval of 2 feet. Accuracy of the contours with respect toelevation is 1/2 contour interval or better.


33/69

4635

\\x'"X__x __ x __ --x- ,~f -x "--- Post-excavation ground profi IeTrench No.2 I Station 1-69

4630

- =c 4640._ g0>Q J

4635

II '> f

I , /- , ' I " \'__Post-excavation ground profile*" - ..x__ X- x . . - r - x-

Trench No. ' I 5>0"00 1-73\_pre- excavation groundprofile4630-20 o 20 30-30 -10 10 40-4 0

Latera I distance from trench center line - ft

Figure 3.8 Typical cross sections for various stages of trench excavation.

3.5 GRAIN SIZE DISTRIBUTIONAfter the trucks were weighed for the bulk density determinations, they were

either dumped in a general waste area or dumped in individual piles for screening todetermine grain size distribution curves. Every fifth load from the trenches and everytenth load from the crater were saved for this purpose.

The material retained for screening was processed by manual and mechanicalmethods into the following sizes: No.4, 3/8, 3/4, 1-1/2, 3, 6, and 12 inches, and3 and 6 feet.3.6 TRENCH MAPPING

Several methods were used to clean and mark the trench walls so that sketch mapsand photographs could be obtained after completion of the trench excavations. Theoriginal ground surface was located, marked, and surveyed. The various zones of ma-terial, such as ejecta, uplift, soil, caliche, etc., were mapped and photographed.Reference points for sketching the separate elements of the exposed trench walls wereprovided by various grid methods.

31


34/69

CHAPTER 4POSTSHOT RESULTS AND DISCUSSION

4.1 BULK DENSITYMeasurements to determine the bulk density (bulking factor) of the ejecta, rupture

zone, and fallback gave results as listed in Table 4.1. This table also includes resultsfrom prior investigations at other craters. The 143-pcf in-situ density used to computethe bulking factor is an average of the dry bulk densities of ten preshot samples takenabove the depth of the explosive cavity.

As can be seen from the table, the bulk density for the ejecta and fallback werevery similar except for Trench No. 1. This same close relationship between fallbackand ejecta was observed at the Pre -Schooner Delta crater. Excluding this single lowvalue in Trench No.1, the average for the remaining three measurements is 103.8 pcf,which gives an average bulking factor of 1.38.

The relatively wide range of bulk densities obtained from the rupture zone(97.6 to 112.9 pcf) is probably due to the varying amounts of overburden included fromtrench to trench and to the differences in bulking that can be inferred from the amountof uplift. As can be seen from the trench profiles, the maximum uplift and overburdenoccurred in Trench No.1 which also had the lowest rupture zone bulk density. Themaximum rupture zone bulk density occurred in Trench No.3 which had the leastamount of overburden and uplift.

32

4.2 GRAIN SIZE DISTRIBUTIONApproximately 20 percent of the material excavated from the trenches and 10 per-

cent of the material excavated from the crater were retained and mechanically screenedto make grain size distribution determinations. In an effort to obtain a representativesample of the excavated material, every fifth load was arbitrarily retained from thetrenches and every tenth load from the crater. To increase further the random samplenature of this selection method, every other load saved from each individual trench wascombined into a single pile and screened separately from the remaining material for thattrench. For example, if loads numbered 1, 6, 11, 16, 21, etc., were saved from atrench, then loads 1, 11, 21, etc., were screened as one group while loads 6, 16, etc.,were screened as a second group. Grain size distribution curves are shown inFigures 4.1 through 4.3. The two different groups are shown as SPI and SP2. Inaddition to this division of material, group SPI from Trench No.3 was further dividedinto SPIA and SPIB.


35/69

TABLE 4.1 SUMMARY OF BULK DENSITIESVolume of Weight ofMaterial Material Bulk BUlkin~Excavated Excavated Densit;z: Factor

ft lb pcfPre-Schooner IITrench No.1 Ejecta 6,874 636,520 93.1 1.54

Rupture Zone 10,346 980,570 97.6 1.47Trench No.2 Ejecta 6,764 694,070 102.5 1.40

Rupture Zone 8,139 918,590 112.9 1.27Trench No.3 Ejecta 11,204 1,172,945 104.2 1.37

Rupture Zone 10,008 1,047,195 104.7 1.37Fallback InsideCrater 214,186 22,430,023 107.7 1.37

Previous Cratering EXQerimentsPre -Schooner ICharlie 13,280 1,335,370 100 1.65

Dugout-' 29,462 3,509,070 119 1.39Pre -Schooner I DeltaTrench No.1 2,250 217,840 97 1.70Trench No.2 5,311 537,010 101 1.63Crater 79,987 7,864,870 98 1.68aE ti f b Iki f t in-situ density . it d 't 143 pcf.qua Ion or u mg ac or: t h t d i; m-S1 u en si y =pos s 0 ensi ybRow crater, five 20-ton charges.

100

90

80

1: 70Ol'Q i~ 60>... ca ; 50t~c 4 0"0a ;Co. 30

20

10

~h, T II" \"0'a~T renc h N o . I - S PII' /1'( /1\ _ '"(~ "0/ I'~

T renc h N o .1 - S P2 / v, I '.J" IT '17. _ ',I '')I ~," ' " ,~ I I . . . . . . "'-ti.II v . . . . . .) I

o10

20

30 - g ,'Q i~4 0

~50 go~60 ~oa ;70 Co.

80

90

o500 100 50 10 5 0.5 0.1 0.05 0 .0 1 0 .0 05

000.001

G rain size in inc he s

Figure 4.1 Grain size distribution curve for Trench No. 1.

33


36/69

100

90

SO

1: 70OJ'Q j~ 60>-...c~ 50~C 40. ,u~"- 3 D

20

10

. . . . "" \\'\ i \ i '\ I Ii"", ~ III II\ 'b. r-- Trench No. 2 - S P 1r\ . / ih V~ \~ -...c50 S li50u60 C. ,u~70 ""-80

90

1000.001


37/69

100

90

80

1: 700>'Qj;: 60>--"Q ; 50c!;:C'" 40


38/69

. . . .. . . . . . r : : :. . r : : : OJ0) Q. )~ ~> -> - . . . a. . . a . . .. . . Q. )V>Q. ) . . .c 0L ; : : : 0o. . . . . . . .c 0Q. ) cu Q. ). . . oQ. ) . . .a... Q. )a..

36

Grain size-in.

80 80. . . .

. . . . . r : : :.s: OJOJ (I)~ ~60 60 > -> - . . . a. . . a . . .. . . (I)V>(I) . . .c 0L ; : : : 0o. . . . . .c 4 0 4 0Q. ) cu (I). . . oQ. ) . . .a.. Q. )a..

o Crater20 v Trench No. 200 Trench No.3

Trench No.20 0100 10 0.1

Grain size-in.Figure 4.5 Comparison of predicted block size for two major materials, and postshotfallback and ejecta mechanical analyses.


39/69

TABLE 4.2 DISTRIBUTION OF ROCK TYPE IN LIP EJECTA WITH RESPECT TOSIZE

Trench No.1

VitrophyreVitrophyre Breccia Felsite Other

inches6 - 12

No percentages obtained 12 - 36above 36

5 7 76 12 6 - 123 3 83 11 12 - 360 0 100 0 above 3651 2 45 2 6 - 1278 0 22 0 12 - 360 0 0 0 above 36

Trench No.2

Trench No.3

TABLE 4.3 PRESHOTPERCENTAGE DISTRIBUTION OF ROCK TYPES WITHINCRATER AREA

Trench No.3

Vitrophyre Trench No.1Vitrophyre Breccia Felsite% % %

EntireArea 25 33 42NorthwestZone 0 41 59NortheastZone 52 22 26South Zone 22 38 40

4.3 TRENCH MAPPINGAfter the trenches were excavated, one wall of each trench was examined and

mapped to delineate the true crater boundary and amount of uplift. The results of thismapping are shown in Figures 4.6 through 4.9 for Trenches No.1, and No.3. The truecrater radius and amount of uplift are listed in Table 4.4.

From an examination of the trench profiles, it can be seen that in all three trenchesthe soil and caliche have been removed from above the uplifted bedrock for a distance of8 to 24 feet back from the true crater zone. This condition is probably the result ofsurface spalling. In Trench No.1 there has also been overthrusting of wedges of mate-rial which, prior to the detonation, constituted the ground surface closer to SGZ.

37


40/69


41/69

-39-

CI)cc 00 N 0'';: CI) 0-C . . .> ::J0+-Q) 0...::J~0

CI)4- .-- i0. . . . r-i0... r o.s : ~0 . . . . ,C 0 rJ J~ M (1)0+- ~. . . . ."0 . . . . . .c INu .. 0. . .)

Q) 0N Z"'C0 C .. cl{') ::J o0 cI-0) QJQ) Hu t-f.E S. . . .::J 0R II) HE 'H0 rJ JI-. . . . . . QJQ) r-i. . . . .U 'H

"'C C 0C C H::J 0+- o, .!!!. . . 0 "'C '00) 0- s ::0+- . S ! ;:i0 0. . . s : : : . 0... "'C HII) 0 C- I- ~ C JII) "'C0 Ca.. ::J t-o ~. . . .0) 0 QJ

C N HC ;:i0) b .O'Ml- Ii!0

0MN

ol{')No 000~ ~ ~ ~" < t " < t " < t " < t~j-1 SW aAo90 uOHAaI3


42/69

-40-

.~uu(l). . ...1)(l). . .>-. . . . ca . . .o. . .. . . .

~o. . .a . . .(l)u.E: JV'>

"0.s:V'>. . . .(5a . . . '1 : lC::>o. . .[J)

'1 : l(l). : : :a . . .::> (l)

'1 : lc::>o. . .[J)oc[J). . .o

oc[J)o

o 0 0C") N-o -o -o"< t "< t "< t~j-1SW


43/69


44/69

TABLE 4.4 UPLIFT AND TRUE CRATER RADIUSBearing from

Trench No. SGZ True Crater Radiusfeet

1 N 56 W 1002 N 18 W, west wall 962 N 18 W, east wall 943 S 35 E 111

Upliftfeet177415-1/2

42

Overthrusting is also evident in Trench No.2; however, in this case it is considerablyfarther back from the true crater boundary zone (roughly 160 feet from SGZ) and ismanifested as the rotation of a large boulder and variation of the ground surface oneither side of the boulder . No visible thrusting occurred in Trench No.3, but thetilted and curved nature of the caliche at the true crater boundary suggests an over-turning of at least the soil and caliche zones. These overturned materials are alsoevident slightly farther back in the trench profiles.

All the trenches were closely examined below the original ground surface in anattempt to determine the nature and extent of blast-induced fracturing. Although somefracturing which could be attributed to the detonation was observed, the nature of themedium is such that no quantitative analysis could be made.4.4 GENERAL OBSERVATIONS

Prior to and during excavation of the Pre-Schooner II crater, some general ob-servations were made concerning slope adjustments and conditions.

4.4.1 Slope Adjustments Prior to Postshot Excavations. Examination of aerialphotographs taken at intervals after the detonation indicates that the slopes did notchange appreciably with time. Shot day was 30 September 1965; photographs were takenon 1 October 1965, 30 November 1965, and 17 March 1966. The most visibly noticeablechange which occurred was the accumulation of the coarser material in the bottom ofthe crater. Since no visible failures in the fallback slopes occurred during this period,it is assumed that the slopes formed by the detonation constituted the "angle ofdeposition" (Reference 14) for the material. The minor slope adjustments which didoccur were the result of weather elements, such as wind, rain, and snow. Some of thesurficial segregation of particle sizes may have occurred during these minor adjust-ments.

When excavation inside the crater was started, it was evident that coarse layeringof grain sizes existed in the upper 4 to 5 feet of fallback, particularly in the bottom ofthe crater. This layering is illustrated schematically in Figure 4.10.


45/69

Coarse materialMedium

Figure 4.10 Diagramatic segregation of block sizes in crater.

4.4.2 Slope Adjustments During Postshot Excavations. During excavation of thetrenches as discussed in paragraph 3.3, the crater slopes were continually failing orsloughing. The fallback was excavated primarily along two radials from SGZ. Byexcavating in this manner, the slopes which were initially standing at their angle ofdeposition were gradually undercut (i, e., the slope toe was continuously cut away).When a vertical face, ranging in height from 2 to 6 feet at the slope toe was developed,the slope would begin a progressive sur-

ficial failure which eventually reached thetop of the crater. This mode of failure isillustrated in Figure 4.11. The upslopeface of these failures always remainednearly vertical. The time ittook for oneof these failures to progress to the craterlip varied from several hours to severaldays. The amount of material involvedwas always small; however, there weregenerally several failures of this typeoccurring at anyone time.

Zero pointFigure 4.11 Diagramatic illustration ofmode of failure during fallback excavation.

4.4.3 Slope Angles. The angle of repose for a cohesionless material is the maxi-mum possible inclination of a slope of that material. The angle of deposition has beendefined as the inclination of a slope formed by the deposition of cohesionless material

43


46/69

....JV'):E. . . .4-4600c:0:j:0>Q)

w

4575

Line Angle TypeofangleC D 37 FallbackslopeG ) 42 Maximumslope

4625 38 Readjustedslope171,000-lb NM

and depends both on the character of the material and the mode of deposition(Reference 14). For all practical purposes, the fallback material at Pre-Schooner IIcan be considered cohesionless. Therefore, the crater slope angles, prior to anypostshot investigations, represented the angle of deposition for this material. Thisaverage angle was 37 degrees. The slopes in part of the crater were then steepened byundercutting the toe of the slope to an average inclination (angle of repose) of 42 degrees.After a short period of readjusting (approximately 1week), the slope stabilized at38 degrees. Figure 4.12 illustrates the various stages of slope stabilization. A lateraerial photograph and topographic map obtained in June 1967 (Figures 4.13 and 4.14)shows that the undercut slopes which readjusted to 38 degrees were remaining at thatangle. In other parts of the crater where the slopes were much steeper, readjustmentto flatter slopes is occurring. Long term slope adjustments will be examined periodically.

Date Condition1Oct 65 Initial condition17Mar 66 Start of undermining--- 12Apr 66 Completeundermining

-------- 2May66 After readjustment

25 50 75Lateraldistance - ft

100 125 150

Figure 4.12 Profiles bearing S40W of apparent crater illustrating slope adjustmentstages (Reference 14).

44


47/69

45

doon. . . . ,cO:>cO()> 1


48/69

rei)~ & : ~~-(\!~,.V d 4,]~"I~)J ' -QIIr~-\ C : , 4 . t". .!~' ...

r>D

--,\----+-___j___L_C~--L---.---Jl2---~IFigure 4.14 Topographic map 14 months after completion of excavation.

46


49/69

CHAPTER 5CONCLUSIONS

The following conclusions can be drawn from the results of the Pre-Schooner IIpostshot investigations:

1. Results obtained from the Pre-Schooner II postshot explorations indicate thatthe fallback materials have essentially the same characteristics as the ejecta so far asoverall bulk density and block size distribution are concerned. This was also found tobe the case at the Pre -Schooner I Delta crater in basalt. Itis also apparent that thebulking factor varies from one hard, dry rock medium to another as evidenced by theaverage of 1.38 at Pre-Schooner II compared to the average of 1.66 in the BuckboardMesa basalts (excluding Project Dugout data, a row -cratering experiment).

2. Block size distribution curves of the ejecta and fallback compared to predictedcurves based on evaluation of preshot data showed relatively good correlation. Thissame relatively good correlation was also noted in the Buckboard Mesa basalt crate ringexperiments. However, the predicted curves for Pre-Schooner II were based solely ona visual examination of the access hole and shot cavity (due to the nature of the rock,core from the exploratory holes and the borehole photography were unusable for jointanalysis), whereas previously predicted curves were based on averages of the linealjoint intercept of a number of borings.

3. Examination of the radial trenches showed lip upthrust ranging from 4 feet inTrench No.2 to 17 feet in Trench No. 1. This variation was also observed at theDanny Boy crater. At Danny Boy the upthrust was exposed all around the crater andcould be mapped. At Pre-Schooner II the upthrust was exposed at the south side of thecrater as a result of sloughing of the fallback during excavation. Although it was notmapped along the south rim, the upthrust was observed to be highly variable.

4. Each of the lip trenches was deepened as far as possible and then examinedfor blast-induced fractures and increased effective porosity. Some fresh fracturing wasobserved close -in in all three trenches; however, the nature of the material was suchthat no detailed study could be made. Based on the great amount of upthrust in two ofthe trenches and the highly variable rupture zone bulk densities it must be concluded thatthere has been some increase in effective porosity.

5. The change in slope angle from the initial 37 to 42 degrees caused by excavatingthe fallback and then readjustment to a stable condition at 38 degrees is an indicationthat the initial crater formation results in relatively stable crater slopes. This meansthat the slopes resulting from this detonation are stable provided no disturbing forcesare introduced.

47


50/69

6. The postshot exploratory techniques developed to date for investigating hard,dry rock craters are only partially successful in accomplishing the major objectives.The procedures employed produce very reliable data on ejecta bulk density and blocksize distribution and overall fallback bulk density and block size distribution. However,these same procedures do not allow for obtaining variations of either the bulk densityor block size distribution within the fallback. Determination of the true crater radiusand amount of upthrust is easily established at each of the excavated trenches; however,these values vary at every point around the crater and existing exploration methods donot provide this additional data. Also, it was not possible to determine the limits ofthe fallback-rupture zone at depth because of the inability to obtain good core recoveryin this particular rock type.

48


51/69

REFERENCES

1. R. J. Lutton, F. E. Girucky, J. L. Decell and R. W. Hunt; "PreshotGeologic and Engineering Properties Investigations, Project Pre -Schooner II";PNE-509; U. S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi(in preparation).

2. R. J. Lutton, F. E. Girucky and R. W. Hunt; "Geologic and EngineeringProperties Investigations, Project Pre-Schooner"; PNE-505F; April 1967; U. S.Army Engineer Waterways Experiment Station, Vicksburg, Mississippi.

3. R. J. Lutton and F. E. Girucky; "Geologic and Engineering PropertiesInvestigations Project Sulky"; PNE-720, November 1966; U. S. Army Engineer Water-ways Experiment Station, Vicksburg, Mississippi.4. R. J. Lutton; "Geologic and Engineering Properties Investigations, ProjectDugout"; PNE-602F; U. S. Army Engineer Waterways Experiment Station, Vicksburg,Mississippi (in preparation).

5. R. C. Nugent and D. C. Banks; "Engineering-Geologic Investigations,Project Danny Boy"; PNE-5005, November 1966; U. S. Army Engineer WaterwaysExperiment Station, Vicksburg, Mississippi.

6. Alton D. Frandsen; "Postshot Field Investigations Buckboard Mesa, NevadaTest Site"; NCG/TM 65-4, 9 August 1965; u. S. Army Engineer Nuclear CrateringGroup, Livermore, California.

7. Roger Paul; "Surface Geology of the Pre-Schooner IIArea"; NCG/TM 65-3,13 May 1965; U. S. Army Engineer Nuclear Cratering Group, Livermore, California.8. Roger Paul; "Geologic Examination of the Access Shaft and Explosive Cavity

for Project Pre-Schooner II; NCG/TM 65-11, November 1965; U. S. Army EngineerNuclear Cratering Group, Livermore, California.

9. R. T. Stearns; Lawrence Radiation Laboratory, Livermore, personalcommunication, July 23, 1965.

10. S. M. Hansen, N. M. Short, and D. E. Rawson; "Report of PreliminaryGeologic Investigations of the Proposed Schooner Site Bruneau Canyon, Idaho";4 October 1963; Lawrence Radiation Laboratory, Livermore.

11. L. M. Gard and J. W. Hasler; "Geology of Proposed Schooner Site, BruneauRiver Area, Owyhee County, Idaho"; USGS Technical Letter, Schooner -3;25 September 1963; U. S. Geological Survey, Denver, Colorado.

12. B. C. Hughes; "Project Pre-Schooner IITechnical Director's SummaryReport"; PNE-507, December 1965; U. S. Army Engineer Nuclear Cratering Group,Livermore, California.

49


52/69

13. P. R. Fisher and R. Paul; "Prediction of Fallback and Ejecta Block SizeDistribution - Project Pre-Schooner II"; NCG65-317, 27 September 1965; U. S. ArmyEngineer Nuclear Cratering Group, Livermore, California.

14. B. N. MacIver; "Formation and Initial Stability of Slopes on CohesionlessMaterials"; PNE-5009, August 1967; U. S. Army Engineer Waterways ExperimentStation, Vicksburg, Mississippi.

50


53/69

APPENDIX A

RESULTS OF PRESHOTUPHOLE SEISMIC SURVEY

(Extracted from Lawrence Radiation LaboratoryInternal Memorandum, R. T. Stearns to A. Holzer,dated 23 July 1965)

51


54/69

TABLE Al SEISMIC UPHOLE SURVEYTime Average

Shot Slant Distance from Shot VelocityShot Depth ( 2 ~tOGeOPhOne from Shot InternalNo. Ds Ds+ojs Tsd to Surface .6.D .6.T Velocityfeet feet sec ftj sec feet sec ftjsec

1 108.0 108.00 0.0166 6,510 9.6a 0.0007a 13,714a2 98.0 98.40 0.0159 6,180 9.8 0.0006 16,3333 88.0 88.60 0.0153 5,7904 78.0 78.70 Misfire No data 19.9 0.0023 8,6525 68.0 68.70 0.0130 5,280 9.8 0.0014 7,0006 58.0 58.90 0.0116 5,075 9.7 0.0012 8,0837 48.0 49.20 0.0104 4,725 9.9 0.0015 6,6008 38.0 39.30 0.0089 4,420 5,5889.5 0.00179 28.0 29.80 0.0072 4,320 9.2 0.0017 5,41110 18.0 20.60 0.0055 3,750 7.8 0.0014 5,57111 8.0 12.80 0.0041 2,850

0 0 2,850

aEntry in this column is read between the two depths shown inShot Depth column atleft.

52


55/69

40

v = 5500 ft/sec20

v = 7775 ft/sec

4 12O~-L __L--L__L--L__L-_L__L-_L~L__L~ __J_~ __ J_~ __ ~~ __ ~~o 16 208

Time - msecFigure Al Average velocities (slant-distance corrected)

53


56/69

. . . . .. . . . . .60...c. . . . .0..Q)Cl

120 I I I I I I I I I I I I I I I I

-V:= 13,714 ft/sec- -

V :=16,333 ft/sec-

- V :=8652 ft/sec -f- -

V :=7000 ft/secf-- -~V = = 8083 ft/sec

f-

V = = 6600 ft/secf-- -.---

V = = 5588 ft/secf-V = = 5411 ft/secf-- -V = = 5571 ft/sec -'

V :=2850 ft / secI I I I I 1

100

80

40

20

o a 4,000 8,000 12,000 16,000 20,000Velocity - ft/sec

Figure A2 Internal velocities.

54


57/69

..J::. . . . .a.(1)o

o 2000 4000Velocity - ft/sec

6000 8000

Figure A3 Average velocities from shot to surface (slant-distance corrected).

55-56


58/69

APPENDIX B

PRESHOT BORING LOGSOFPRE-SCHOONER II SITE AREA

57


59/69

BORING 2.1

blac:k, moderatel:; hard; 10 to15~ f~ldsp


60/69

s;:laSSYi dark r yay, dense no....alternat1nr; vith brevn, porouslayers ( to 1 in. thic:k) ':lipping70 to 90 deB; 10 fdd~r cuhedrfl.!1/16 to 1/8 in. across; l~ voi1sin poroUIIla;rersj steep 1 In. vein-bt, orangeglass shArds to 37 ft.rockbreeJt. byte.ps at '-er tol/B-ln, chips locally.

BORING 2.7

no sl:;nl!'lc",!".tair lossin t~l~ :'101".

11 to 25 r e, cor -eaveA,-:e 9 in.

0.6 to 20.6 re, holegrouted.

~5 to 40 ft, eor-e !leg-llIentllless than 1/2 in.to 6 In.

40to 56 rt, con sel-mented to less than1/2 In. up to 1_1/2in.on jOints and flovlayers.

44 to 52 ft, groutedafter eDcountc:ring4 :rtrall-in at 50ft.

I56 to 61 tt. core seg_l Il en ts 1 to 2111.

85 to 105 :rt, ecre leg-!lent. 1 to 6 in.

6, "0604 ,4090

59

PROJEG" l' PRE -SC I !OON I :R I I2.7 (Continued)

LOC.o.TIO'_ (IWO ST.o.TE coowou .....Tsl

C ; : O R E 1 - ; . ; ; ; ,~ ; : - r _ : : J o : :: m r : ; - : ' " : :: T . : : A ,-----1RECOV. "T ~

~lOO~ : FELS ITE (as above)\!./I'/;:

Bottom of hole

IC O re . .. .. .. t. 01' f'rapeDt. &wnp:2 in. or rt.np 1 ill. to 6 In.


61/69

_0.5 to 46.4 tt, 5_ -uvesicle. dipping 30 to 50. . . .

lost all aiT returnat 40 ft.

BORING 2.10

45

8580804530803.6.4534545

, .55M4.80~

50.6 to 67 tt, drUl.1zIIchatacteristie. tuge.tJoint. as above; ~.epeot. le.. tha.n 1 in.to 3 in.

61 to 115 tt, -o.t eorelea-nts 1-1/2 to 3 In.1 0 " " .Irepined ~_ a1r return

at 70 tt, m rn. 72 ttto bottal.

95to 101 tt, 1IIlIborl-100 SODtal .)oift'tI, 2 tn._,-..

2. 0 (Continued)

! ! ! :1! : ! ! (as above)

nov layer. dip 0 to 10 deg.

110to 11~ft,t1eh.t. Joint.coated rlth calcite parallelno v l.a~TS. 110.4 to 114 rt,elo.ed,wbpanllel Joint.spt.ced 1/4 to 1/2 In.I IIIott,a,; ot hole

D sue and Rook , .,. .. .. 0'"

~ Felsite, glau)"WRFddte~

60

% JOllft'WAco. .., ~.",,~,",-==r=T----lRICOV . "'T ! ~

100

IFnpents aver~ 1 in. OJ' lWIIe~ leu the.n 1 In. to 2 In.ICore legaents or tragllents average2 in. OT Tange1 In. to 6 In.

Point.. o~ interseetlon otiDdiv1dual Joints withdip as indie.ted.


62/69

BORING 2.11

blaek, vesicul .ar, g l.&ss ..nth 15"feldspu euhedra 1/16 in. long;15 to 251>by volume flattened,l1ne!l.ted vesicles 1/16 to 1/8 in.long, dipping 80to 90deeat15 ft, 30 to 50 dee at 25 ft.cxt dfaed to red around vesicles1n lover 10 ft; proba.bly in parta breccia wit h I!II!.t rix lost bygrinding.

nosignificant air 10s5i n this hole. groutedto 20.] ft.

10to 46ft,COfe seg-lI1entedlto31n.;partly by dril l break-age alone incipientJoints_

56 to 59.3 ft. Jointssubparallel to flo . .. .I e. yc r s j spn. c~c 1 to31n. I I1.6 to 73 ft,core 5eg-ncrrts f[l.ncC 3/4 to 2In. , mos 't .Ly on closelyspac.-: .r ljolnts; d ipjOto 90 cleC'

'{j to : :, 0 ! 't ,COl "C ' ~ .ecnt s aVI'r, ', 'in part, 'rill::,_o"tl;"i'wl"i,nt

'. ,roo90c -o-;0,0

61

DSiltMdRod


63/69

"1 tc 54 tt, 51 nat vesiclesdip 30 to 40 lllJolr.t~ Hp 1') to : = o t " l '!"";.

I

,11(,to 120ft, ecrese.l'}l!ents1 to 20 lr..

W : . i - = , - - . - - _ . . : J c : _ : o n , , " r : = . ; : ; , ' . - _ - - lI'JC'tollf,!'t.o:on.:ie.:l=ler. t~1 to (_ In.

I ~:..,.~"!onln,.~.tjol~.t s':t~i ' :1 ;> ;0 o,.n~ :_;') 10:: ; : .~j 100113 to ll~ !'to, 3/t to i-w, ~breed. ted vein vlth calciteand elay, dips ~5 deg. 100u6 to 120 rt,_ be brc*eD 'byt.ap. of ~ to ~1D. tnc- I..rt.., -.ny .)o1at. puaUel tota1at flov ~. 41pp1lll 100o to 1 0 4 11 1.

62

Bott.om of hole

r J , ' , ' , : , FragJllent:oa.verll{;~1 in. or r~e~j le~. than 1 In. to 2 In.

::::::J,o Po1nt~o!' inter~ect1on ofrl20 Inc!J.v1dI.1I1Joint" vltht: 1.5 dip a~ In11clted.

Dvtt"'Phr..

nFelsit"e, glaSilY00


64/69

APPENDIX CPRE-SCHOONER II TECHNICAL REPORTS

Author and/or Techni- ReportTitle of Report Agency cal Program Officer Number----Technical Director's NCG B. C. Hughes et al. PNE-507Summary ReportApparent Crater Studies NCG R. H. Benfer PNE-508Preshot Geologic WES/NCG W. C. Sherman, Jr./ PNE-509Investigations and R. A. Paul et al.Engineering PropertiesDesign and Postshot WES K. L. Saucier PNE-510Evaluation of AccessHole StemmingBase Surge and Cloud NCG/LRL W. C. Day/R. F. PNE-511Formation RohrerAir Blast Measure- SC L. J. Vortman/ PNE-512ments J. W. ReedSurface Motion NCG K. L. Larner PNE-513MeasurementsGround Shock Roland F. L. L. Davis PNE-514Measurements Beers, Inc.Subsurface Effects LRL M. Heusinkveld/ PNE-515Measurements R. E. MarksPostshot Geologic NCG A. D. Frandsen PNE-516Investigations andEngineering Properties

63


65/69

DISTRIBUTION

LRL Internal DistributionMichael M. MayR. BatzelJ. BellJ. CarothersW. DeckerS. FernbachH. L. ReynoldsJ. GofmanE. GoldbergJ. HadleyW. Harford

30

C. HaussmannP. MoulthropG. HigginsA. HolzerE. Hulse

2

J. KaneJ. KnoxJ. KuryF. EbyM. NordykeJ. RosengrenB. RubinD. SewellP. StevenesonH. TewesC. Van AttaG. WerthTID BerkeleyD. M. Wilkes, BerkeleyE. Teller, BerkeleyL. Crooks, MercuryTID File

2

2

22

64


66/69

External DistributionD. J. ConveyDepartment of Mines and Technical SurveysCanada

2

G. W. GovierOil and Gas Conservation BoardCanada

2

U. S. Army Engineer Division, Lower Mississippi ValleyVicksburg, MississippiU. S. Army Engineer District, MemphisMemphis, TennesseeU. S. Army Engineer 'District, New OrleansNew Orleans, LouisianaU. S. Army Engineer Waterways Experiment StationVicksburg, Mississippi

15

U. S. Army Engineer District, St. LouisSt. Louis, MissouriU. S. Army Engineer District, VicksburgVicksburg, MississippiU. S. Army Engineer Division, MediterraneanAPO, New YorkU. S. Army Liaison DetachmentNew York, New YorkU. S. Army Engineer District, GULFAPO, New YorkU. S. Army Engineer Division, Missouri RiverOmaha, NebraskaU. S. Army Engineer District, Kansas CityKansas City, MissouriU. S. Army Engineer District, OmahaOmaha, NebraskaU. S. Army Engineer Division, New EnglandWaltham, MassachusettsU. S. Army Engineer Division, North AtlanticNew York, New YorkU. S. Army Engineer District, BaltimoreBaltimore, MarylandU. S. Army Engineer District, New YorkNew York, New YorkU. S. Army Engineer District, NorfolkNorfolk, Virginia

65


67/69

External Distribution (Continued)U. S. Army Engineer District, PhiladelphiaPhiladelphia, PennsylvaniaU. S. Army Engineer Division, North CentralChicago, Illinois

U. S. Army Engineer District, BuffaloBuffalo, New YorkU. S. Army Engineer District, ChicagoChicago, IllinoisU. S. Army Engineer District, DetroitDetroit, MichiganU. S. Army Engineer District, Rock IslandRock Island, Illinois

U. S. Army Engineer District, PittsburghPittsburgh, Pennsylvania

U. S. Army Engineer District, St. PaulSt. Paul, MinnesotaU. S. Army Engineer District, Lake SurveyDetroit, MichiganU. S. Army Engineer Division, North PacificPortland, OregonU. S. Army Engineer District, PortlandPortland, OregonU. S. Army Engineer District, AlaskaAnchorage, AlaskaU. S. Army Engineer, SeattleSeattle, WashingtonU. S. Army Engineer District, Walla WallaWalla Walla, WashingtonU. S. Army Engineer Division, Ohio RiverCincinnati, OhioU. S. Army Engineer District, HuntingdonHuntington, West VirginiaU. S. Army Engineer District, LouisvilleLouisville, KentuckyU. S. Army Engineer District, NashvilleNashville, Tennessee

U. S. Army Engineer Division, Pacific OceanHonolulu, HawaiiU. S. Army Engineer District, Far EastAPO, San Francisco, California

66


68/69

External Distribution (Continued)U. S. Army Engineer District, HonoluluHonolulu, HawaiiU. S. Army Engineer District, OkinawaAPO, San Francisco, CaliforniaU. S. Army Engineer Division, South AtlanticAtlanta, GeorgiaU. S. Army Engineer District, CanaveralMerritt Island, FloridaU. S. Army Engineer District, CharlestonCharleston, South CarolinaU. S. Army Engineer District, JacksonvilleJacksonville, FloridaU. S. Army Engineer District, MobileMobile, AlabamaU. S. Army Engineer District, SavannahSavannah, GeorgiaU. S. Army Engineer District, WilmingtonWilmington, North CarolinaU. S. Army Engineer Division, South PacificSan Francisco, CaliforniaU. S. Army Engineer District, Los AngelesLos Angeles, CaliforniaU. S. Army Engineer District, SacramentoSacramento, CaliforniaU. S. Army Engineer District, San FranciscoSan Francisco, CaliforniaU. S. Army Engineer Division, SouthwesternDallas, TexasU. S. Army Engineer District, AlbuquerqueAlbuquerque, New MexicoU. S. Army Engineer District, Fort WorthFort Worth, TexasU. S. Army Engineer District, GalvestonGalveston, TexasU. S. Army Engineer District, Little RockLittle Rock, ArkansasU. S. Army Engineer District, TulsaTulsa, OklahomaU. S. Army Coastal Engineering Research BoardWashington, D. C.

67


69/69

External Distribution (Continued)Mississippi River CommissionVicksburg, MississippiRivers and Harbors, Boards of EngineersWashington, D. C.Corps of Engineers Ballistic Missile Construction OfficeNorton Air Force Base, CaliforniaU. S. Army Engineer CenterFt. Belvoir, VirginiaU. S. Army Engineer Reactors GroupFt. Belvoir, VirginiaU. S. Army Engineer Training CenterFt. Leonard Wood, MissouriU. S. Army Engineer SchoolFt. Belvoir, VirginiaU. S. Army Engineer Nuclear Cratering GroupLivermore, California 74

TID-4500, UC-35, Nuclear Explosions - Peaceful Applications 292

L EG A L N O TI C E

T ills re po rt I 'I ~S p re pa re d a s a n a cc ou nt o f G o v e n u r e n t s po ns or ed w or kN ed lle r th e U mte n Sta le s, n or th e COnln'ISSIOIl, 1 1e 1a ny p ers on a ct in g o e b e h al!o f W e Co sm ts s to n :

A M J~ es a ny w au an ty or re cr ese nta nor. e rore sse d or Im plie d, w ithr es pe ct t o tile a cc uo cy . c om ple te ne ss o r u se fu ln es s o f Ih e in fo rm a tio n c on -la rn ed in th is re po rt. o r th at th e u se of a ny in fo rm atio n, a pp ara tus . m eth od , o rp r oc e ss d i sc lo s ed i n t h is re po rt m ay n ot in f r inge p ri va te ly o wn e d r igh ts; 01

B Assu me s a ny lia bilitie s w ilt. re sp ect 1 0 th e u se of. o r for d am ag esre su ltin g n om Ih e u se o f a ny tn tc rm at-o n, a pp ara tu s. m eth od or p re ce ss d rs .c lo s ed i n I h is r ep o rt

As use d in th e a bove . "p erson a ctin g on be ha lf of th e C om mission "in clu de s a ny e mp lo ye e o r c on tra cto r o f th e C om mis sio n, o r e mp loy ee o f su chco ntra ctor. to th e e xte nt th at s uch e mp lo ye e o r c on tra cto r o f th e C on miss io n,o r e mp loy ee o f su ch c on tra cto r p re pa re s, d is se min ate s, or p rov id es a cc es s 1 0,a ny in fo rm atio n p urs ua nt to h is e mp lo ym en t o r co ntra ct w ith th e C om mis sio n.o r h i s e m pl oy m e nt w it h s uc h c on tr ac to r.

pne 516 Pre-Schooner 2

Documents

Transcript of pne 516 Pre-Schooner 2